With most baked goods, microbial spoilage comes from post-bake contamination. That’s because the high temperatures encountered in the oven typically kill off microbes.
Dust particles can carry many microbes, and certain areas of a bakery have higher concentrations of dust particles in the air than others, according Mr. Guilfoyle. “Segregating a cooling/packaging area away from areas with high dust particle counts will reduce the amount of microbial inoculation on a finished product, thus allowing antimicrobials to be more effective,” he said.
Because mold spores are ubiquitous, even in the cleanest of bakeries, mold growth may occur prior to an expiration date unless steps are taken to retard such activity. Such issues are greatest in products with high water activities because molds thrive on moisture. Because a bakery’s warm, moist environment is conducive to mold proliferation, particularly susceptible products, namely breads and buns, can benefit the addition of ingredients that bind water. These ingredients protect the bread from viable mold spores in the environment.
“High-moisture products and those with a higher pH are prone to mold,” said Courtney Schwartz, senior marketing communications manager, Kemin Food Technologies. “An antimicrobial can help with this. Our liquid antimicrobial line provides great protection through a highly concentrated formula that gives even dispersion throughout the product with no negative sensory impact.”
Some such ingredients provide additional benefits. For example, the liquid antimicrobial Ms. Schwartz cited can help corn tortillas remain pliable and soft.
“Traditional mold inhibitors such as calcium propionate and potassium sorbate are not perceived as clean label by consumers, whereas vinegar is much less scrutinized,” Mr. Guilfoyle said. “The main issue with these inhibitors is that we’ve had to increase usage levels as stale-free shelf life increased. Excessive use can result in off flavors.”
DuPont offers a natural mold inhibitor derived by fermentation. It contains natamycin, which is very effective against mold but has no impact on bacteria. It is typically applied via a spray on bread products after they exit the oven. In certain applications, it is used directly in the formulation.
“It works by disrupting the mold cell membranes,” Mr. Guilfoyle explained. “Traditional mold inhibitors slow the growth of mold, whereas this ingredient has the ability to kill it.”
Finding a good package is the best barrier to prevent further microbial inoculation, Mr. Guilfoyle added. It also provides a barrier for moisture migration from the finished baked product to the outside, slowing down or preventing further oxidation.
Learn all about fat oxidation in the next segment.